Higher education and academic research institutions have long been used by China's tobacco industry to promote business on the mainland, sometimes in a misleading manner, according to a new study.

Conducted by the Chinese Center for Disease Control and Prevention and the International Union against Tuberculosis and Lung Disease, the study found increasingly close ties between the two parties during the past 30 years.

Most studies surveyed deal with tobacco farming, manufacturing and management, while the "misleading" ones - often about "reduced harm" tobacco products and their alleged positive health effects - have kept increasing in recent years.